Generally, when an inkjet recording apparatus repeatedly conducts printing operations, foreign materials such as paper powder, dust, viscosity-increased ink, and ink droplet may adhere on a nozzle of a recording head, by which the nozzle of the recording head may be affected, and a deterioration of image quality may happen due to a malfunction of recording head such as nozzle blocking and irregular discharge caused by an adhesion of foreign materials.
In order to cope with such drawbacks, a capping unit and a negative pressure generator may be used, for example. The negative pressure generator sucks ink from the nozzle while the nozzle is capped by the capping unit.
Furthermore, a wiping unit may be used to cope with such drawbacks, for example, wherein the wiping unit scrapes and removes foreign materials from the nozzle.
In addition, a dummy discharge can be conducted before re-starting printing after leaving the nozzle without discharging fresh ink for some time. In the dummy discharge, fresh ink is discharged from the nozzle without actual printing operation to remove viscosity-increased ink on the nozzle.
Furthermore, such inkjet recording apparatus includes a waste ink processing unit for storing waste ink used in ink suctioning or dummy discharge operation, and the waste ink processing unit includes an absorber for efficient storing of waste ink.
However, when the nozzle is cleaned by the wiping unit having wiping blade, viscosity-increased ink may stick on the wiping blade. When another cleaning is conducted by such wiping blade having the ink stuck thereon, such ink may move onto the nozzle, or intrude inside of the nozzle, by which discharge-ability of the nozzle may deteriorate.
Furthermore, when viscosity-increased waste ink in the waste ink processing unit sticks, such ink may not be absorbed by the absorber in the waste ink processing unit, and waste ink may spillover from the waste ink processing unit.
Furthermore, after the ink suctioning is conducted on the nozzle, ink remaining on the capping unit may increase its viscosity, and may be dried. If such capping unit is used for capping the nozzle for a long period of time, the viscosity-increased ink may become an absorbent, which absorbs water or moisture from the nozzle. If such condition occurs, the nozzle may not be refreshed even if the dummy discharge is conducted.